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How many 3-digit numbers can be formed from first five natural no. assuming that
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document.write( "The first 5 natural numbers are {1,2,3,4,5}\r\n" );
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document.write( "Choose the 1st digit any of 5 ways.\r\n" );
document.write( "Choose the 2nd digit any of 5 ways. That's 5×5 ways to pick the 1st 2 digits\r\n" );
document.write( "Choose the 3rd digit any of 5 ways. That's 5×5×5 ways to pick all 3 digits.\r\n" );
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document.write( "Answer 5×5×5 = 5³ = 125 ways.\r\n" );
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document.write( "Here they all are, 12 rows of 10 and one row of 5\r\n" );
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document.write( "111 112 113 114 115 121 122 123 124 125\r\n" );
document.write( "131 132 133 134 135 141 142 143 144 145\r\n" );
document.write( "151 152 153 154 155 211 212 213 214 215\r\n" );
document.write( "221 222 223 224 225 231 232 233 234 235\r\n" );
document.write( "241 242 243 244 245 251 252 253 254 255\r\n" );
document.write( "311 312 313 314 315 321 322 323 324 325\r\n" );
document.write( "331 332 333 334 335 341 342 343 344 345\r\n" );
document.write( "351 352 353 354 355 411 412 413 414 415\r\n" );
document.write( "421 422 423 424 425 431 432 433 434 435\r\n" );
document.write( "441 442 443 444 445 451 452 453 454 455\r\n" );
document.write( "511 512 513 514 515 521 522 523 524 525\r\n" );
document.write( "531 532 533 534 535 541 542 543 544 545\r\n" );
document.write( "551 552 553 554 555\r\n" );
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document.write( "(b) repetition of the digits is not allowed.The first 5 natural numbers are {1,2,3,4,5}\r\n" );
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document.write( "Choose the 1st digit any of 5 ways.\r\n" );
document.write( "Choose the 2nd digit any of the 4 remaining ways. \r\n" );
document.write( "That's 5×4 ways to pick the 1st 2 digits\r\n" );
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document.write( "Choose the 3rd digit any of the 3 remaining ways. \r\n" );
document.write( "That's 5×4×3 ways to pick all 3 digits.\r\n" );
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document.write( "Answer 5×4×3 = P(5,3) = 60 ways.\r\n" );
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document.write( "Here they all are, 6 rows of 10 each. \r\n" );
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document.write( "123 124 125 132 134 135 142 143 145 152\r\n" );
document.write( "153 154 213 214 215 231 234 235 241 243\r\n" );
document.write( "245 251 253 254 312 314 315 321 324 325\r\n" );
document.write( "341 342 345 351 352 354 412 413 415 421\r\n" );
document.write( "423 425 431 432 435 451 452 453 512 513\r\n" );
document.write( "514 521 523 524 531 532 534 541 542 543\r\n" );
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document.write( "Edwin \n" );
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